speedup camera

[tueddy]

Hi,

nice app and demo!
I've tested on Nokia 6 with Android 8.1.0 with Delphi 10.2.3 and camera-drawing is soo slow and not far from unusable.
Another test with Delphi.ZXing advanced example is much faster and gives the user a smooth feeling.
Demo here: https://github.com/Spelt/ZXing.Delphi/tree/v_3.0/AdvancedTestApp

this is the patch for TCamera component:
https://quality.embarcadero.com/browse/RSP-10592

But i had no success, i assume you do a lot creating/copying bitmaps.

Best
Dirk